Gas vs. Electric Water Heaters Comparison

Compare gas vs. electric water heaters to find which type is the best for your home. The article will help you understand the differences between heaters powered by natural or propane gas and electricity, with the benefits, pros, and cons.

The main factors to consider when choosing the water heater for residential applications are selecting the fuel type - gas or electric, and how does it store water - tank or tankless.

When selecting the type of energy source, you should also consider the fuel availability and the cost, size of the unit, and energy efficiency.

You'll notice that all well-known manufacturers of water heaters in North America, such as Rheem, AO Smith, Bradford White, State, Reliance, Kenmore, John Wood, include models that are mainly fueled by gas and electricity.

Electricity is widely available in North America, while natural gas and propane less. If you have more than one fuel type available in your area, it is a good idea to compare its costs.

Gas vs. electric water heater and factors to consider

Gas water heaterGas water heater

Gas versus electric water heaters, so which one is better?

Below you will find the general comparison of the costs, efficiency, selection, and main elements, including how they work.

In short:

Type Gas water heaters Electric water heaters
Recovery rate + -
Energy Star + -
Initial price - +
Operating costs + -
Easy to install - +
Easy to fix - +


Gas-powered water heaters utilize powerful burners that heat water fast, and as the gas price is cheaper, the operating costs are lower than electric models.

Initial cost when buying the electric type is less than buying a gas water heater, and the installation costs are lower. With the gas-powered units, you must provide a venting system and gas supply line, making them less safe than electric models. Electric models are also easier to maintain.

Electric units can be installed almost anywhere inside the house, especially point-of-use and tankless water heaters, while gas-powered models require a proper location. They need or might need a vent system, sufficient air draw, chimney, proximity of the outside wall, electricity to power vent models, gas line... All these requirements increase the price.

If natural gas is not available in your area, the other option is to use propane gas. Propane is cheaper than electricity but costs more than natural gas, and it requires storage and regular fuel delivery, which contributes to higher costs.

Electric water heaterElectric water heater

Energy efficiency

Energy Factor or EF rating is often used when choosing the water heater. Water heaters with high energy factors are Energy Star compliant, which brings down the operating costs and, at the same time helping the environment – due to lower gas emissions. The utility company could even offer incentives and government tax breaks. So the higher EF, the more efficient the water heater is, but...

Energy factors of gas water heaters ranges from 0.57 to over 0.9 for condensing models, where the EF of 0.67 and higher meet the Energy Star standards. On the other side, electric units have an EF over 0.9, but are not Energy Star approved. 

The only electric-powered heaters that meet the requirements are electrically-operated heat pumps or hybrids. This type of electric water heaters combines heating elements and heat pumps, resulting in higher efficiency and lower energy costs than gas-fired. They cost more than conventional electric and gas types.

The most energy-efficient models you can buy are high efficiency (HE) and condensing.

Recovery rate

The recovery rate (in GPH) is an essential factor when choosing a water heater as it indicates how much hot water is heated in a given time. Most of the 50-gal electric models have a recovery rate of approximately 20 gallons, while gas has around 40 gallons (at 90 F) for the same tank size.

The power of gas models varies from 30,000 to 180,000 BTUs, and the more it has, the faster it will heat the water.

The electric type has heating elements with power ranging from 1,440 to 5,500 watts.


The advanced type of gas heaters uses the gas control valve that provides more reliable and accurate performance, with better temperature control and faster hot water recovery. Such gas valves come with the LCD display or LED diodes, informing users about the status, errors, and other useful info.

Models that are direct vent and use a thermopile do not need the electric power, which is not the case with the electric units, so - no electricity, no hot water.

The only electric units with advanced electronics (smart), such as those found on gas models, are heat pumps.

Gas-powered water heaters tend to have higher recovery rates than electric ones but can waste energy if they are equipped with a pilot light.


When comparing gas versus electric water heaters and reviewing their parts, you can notice that gas models are more complex, therefore, more expensive.

They both use the anode rod, ceramic/glass lining, dip tube, TPR valve, but the main difference is how they heat water.

If planning to install the electric tankless water heater in the old house, it might be required to replace the whole wiring and the electrical panel so the unit can deal with the higher amps.

Gas units require a gas line, gas control valve, gas burner with the combustion chamber, pilot light or electrode, thermocouple, and venting-exhaust system. In contrast, electric units require only heating elements and thermostats to heat the water.


There is a greater variety of gas-powered water heaters than electric, as seen below:

  • Atmospheric vent
  • Direct vent
  • Power and Power-Direct vent
  • Ultra-Low NOx
  • Flue Damper
  • Condensing
  • Water heaters with the pressurized combustion chamber, such as the State Premier high-efficiency model.
  • The hybrid uses both tank-type and tankless technology, such as AO Smith NEXT model.
  • Electric can also be used as a hybrid, and these are known as heat pumps.


Gas units can work with the lower amount of water in the tank as the gas burner is located at the bottom of the unit. At the same time, electric models require water level above the heating elements because they can burn out, resulting in element failure.

How do they work

Gas water heaters, like their electric counterparts, use the water storage tank to store water. Gas uses the gas burner to heat water, while the electric, one or two heating elements.

Gas models utilize a gas control valve with an integrated thermostat to control the gas flow and temperature, while the electric has thermostats attached to the heating elements. Gas on the gas burner could be ignited manually, with the piezo or a hot surface igniter.

As opposed to the electric type, gas models must incorporate vents to remove the product of combustion. These can be direct power, power-direct, and an atmospheric vent.

It is useful to know that some gas models could operate without electricity.

You can find detailed explanations of how does an electric water heater work here. 

For gas heaters and how they work, use this article.

Final thoughts when comparing gas vs. electric water heaters...

In the US and Canada, natural gas provides the most economical way for water heating. If natural gas is available in your area, the recommendation is to buy a gas water heater. If you live in a rural area and there is no supply of natural gas to your home, you have an option to go with the propane gas or electrical type.

From the gas type, look for the condensing models, such as AO Smith Vertex or Polaris. The recommendation is to get a heat pump that comes with high efficiency and Energy Star compliance.